# arcus
## English
### Etymology

Borrowed from Latin arcus. Doublet of arc and arco. Distantly related to arrow.

### Pronunciation

* This entry needs pronunciation information. If you are familiar with the IPA or enPR then please add some!

### Noun

arcus (plural arcus)
* (medicine) A white band of cholesterol that forms at the edge of the cornea
* (meteorology) A low, horizontal cloud typically forming at the leading edge of thunderstorm outflow
* (entomology) An elastic band around the base of the arolium, a pad at the end of the leg of certain insects
* (palynology) An arc-shaped band of thickened sexine extending between two apertures on a pollen grain or spore

#### Related terms

* arc
* arcuate
* arcus juvenilis
* arcus inguinalis
* arcus senilis

#### Translations
### Anagrams

* Curas, carus, scaur

## Latin
### Etymology

From Proto-Italic *arkuos (“bow”), from Proto-Indo-European *h₂erkʷos (“bow, arrow”). Cognate to Old English earh, whence English arrow, as well as Proto-Slavic *orkyta (“willow”) and Ancient Greek ἄρκευθος (árkeuthos, “juniper”), owing to juniper and willow twigs being used to make bows due to their flexibility.

### Pronunciation

* (Classical Latin) IPA: /ˈar.kus/, [ˈärkʊs̠]
* (modern Italianate Ecclesiastical) IPA: /ˈar.kus/, [ˈärkus]

### Noun

arcus m (genitive arcūs); fourth declension
* arc, arch
* bow (arc-shaped weapon used for archery)
* rainbow

#### Declension

Fourth-declension noun (dative/ablative plural in -ubus).

#### Derived terms

* arcifer
* *arciō
* arcipotens
* arcisellium
* arcitenens
* arcuō
* ballistārius arcūs

#### Related terms

* arcuātus

#### Descendants

* Insular Romance:
** Sardinian: alcu, arcu
* Balkano-Romance:
** Aromanian: arcu
** Romanian: arc
* Italo-Dalmatian:
** Italian: arco
*** → English: arco
** Sicilian: arcu
*** → Maltese: arku
* Rhaeto-Romance:
** Friulian: arc
** Romansch: artg, arch
* Gallo-Italic:
** Ligurian: erco
** Piedmontese: erch, erche
* Gallo-Romance:
** Catalan: arc
** Occitan: arc
** Old French:
*** arc
**** French: arc
**** → Middle English: ark, arke
***** English: arc
****** → Irish: arc
****** → Maltese: ark
****** → Welsh: arc
*** arche
**** French: arche
**** Norman: arche
**** → Middle English: arch, arche
***** English: arch
* Ibero-Romance:
** Asturian: arcu
** Old Galician-Portuguese: arco, arquo
*** Fala: arcu, alcu
*** Galician: arco
*** Portuguese: arco
**** → Indonesian: arku
** Old Spanish: arco
*** Spanish: arco
**** → Cebuano: arko
**** → Chibcha: arco
**** → Ilocano: arko
**** → Tagalog: arko, ⇒ alakos
** → Basque: arku
* Borrowings:
** → English: arcus
** → Esperanto: arko
** → Ido: arko
** → Indonesian: arkus
** → Middle Low German: ark
*** Low German: ark
**** → Danish: ark
***** → Icelandic: ark
**** → Norwegian Bokmål: ark
**** → Norwegian Bokmål: ark
**** → Norwegian Nynorsk: ark
**** → Swedish: ark
***** → Finnish: arkki
** → Russian: а́рка f (árka)
*** → Latvian: arka f
*** → Lithuanian: arka f

#### See also

* discus
* sagitta

### References

* “arcus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
* “arcus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
* arcus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
* arcus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
* “arcus”, in Harry Thurston Peck, editor (1898), Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
* arcus in Ramminger, Johann (2016 July 16 (last accessed)) Neulateinische Wortliste: Ein Wörterbuch des Lateinischen von Petrarca bis 1700‎, pre-publication website, 2005-2016
* “arcus”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin
* ↑ De Vaan, Michiel (2008) “arcus”, in Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, page 52